Expenses for radio publicity and/or program broadcasted constitute a high percentage of the costs which any manufacturing and/or selling company and/or TV or radio station have to bear in order to promote sales. It is of particular interest to all of said companies to know to what extent such publicity and/or broadcasted program is successful, and a very significant indication is given by the time during which various groups of possible consumers actually hear the publicity and/or broadcasted program. Among such groups are included drivers and passengers of cars, who hear the publicity and/or broadcasted program while traveling and keeping open the radio receiver, of which all cars are provided.
All radios, at home or mounted in cars are provided with an antenna which may receive radio signals from a number of broadcasting stations. Radio signals are broadcast over specific frequencies, each defining a channel. To operate the radio receiver, one has to tune it, viz. to choose the desired channel, separate it from other channels and extract the voice and/or music carried through said channel. Tuning is done by a device with a very narrow bandwidth filter. In order to be effective, the filter operates at a fixed, low frequency called IF (Intermediate Frequency), which is standard at 10.7 MHz. The antenna is connected to the RF port of a mixer. The mixer also receives an input from an LO (Local Oscillator, generally a Frequency Synthesizer). The mixer is a device that produces sum and difference of the radio signal received and LO inputs. The LO is tuned to a certain frequency f0. Only the signal which differs from said frequency by the standard IF, which is practically 10.7 MHz, will be passed by the filter, while the others will be blocked. The sound, which is carried by the signal that has passed, is extracted, amplified, and transferred to the speaker of the radio receiver. The oscillator was tuned by means of a knob in old stages of the prior art, and still is in some cases, but in modern radios the tuning is performed by a keyboard and/or digital display.
Cable TV operates in a similar mode but in different frequencies. All channels at different frequencies come to the converter. At the converter, a similar process of LO and mixing occurs, which translates all of the frequencies to a single one, to which the TV set is tuned.
Publicity and/or broadcasted program transmitted by radio are heard to a very considerable extent during travel by car. Radio transmissions are widely listened to by drivers, whether professional or not, especially in rush hour time, on the way to work in the morning and on the way back home in the evening, so as to entertain them during journeys and reduce the danger that they may doze off. Since taxi drivers always keep their radio in operation, passengers are also exposed to the radio transmissions, whether they desire it or not. Therefore, an important slice of radio publicity and/or broadcasted program is that which is sounded by car radios.
It would be of considerable interest for companies which engage in publicity and/or broadcasted program to obtain in real time a significant index of the time during which said publicity and/or broadcasted program is heard, which on the average is an indication of the efficiency of said publicity and/or broadcasted program. However, the prior art does not include means for obtaining such an index in real time (by using the term “efficiency” it is meant to include any indication regarding the level of popularity of a radio or television program, as estimated by a poll of segments of the audience).
U.S. Pat. No. 6,643,494 B1 discloses a broadcast survey system configured to identify radio stations to which tuners are tuned. The tuners have local oscillator signals emitted therefrom. The survey system employs a method that includes generating and broadcasting a survey signal that is one of the local oscillator signals, modified to incorporate a signal identifier. This reference also discloses a method for active tuning of the survey system and another method for providing short range communication with remote transceiver to facilitate uploading and downloading of system setting and data.
WO 99/62260 discloses an audience rating system for digital television and radio, using identification codes in control streams of time-multiplexed digital transmission. When a television set or radio, monitored by said system, is turned on and tuned to a channel, and then the channel is changed, each time that it is changed an identification code for each audio, video or auxiliary digital stream of the channel, is extracted from the control stream, and recorded along with the time.
U.S. Pat. No. 3,800,223 discloses a monitor which includes one or more channels provided with a signal pass band window or slot that is swept at a constant rate but stopped when a television local oscillator signal enters the window. If the signal remains in the window for a predetermined time, the signal is counted and the sweep continued.
The aforesaid prior art patents, and in general all the publications of the prior art, as far as it is known to the applicants, do not provide companies that carry out radio publicity and/or broadcasted program with the desired information in real time as to the efficiency of the publicity and/or broadcasted program. This invention intends to provide such information by simple and inexpensive means.
More specifically, it is an object of this invention to provide a method and apparatus, applicable to a group of TV watchers and radio listeners who will agree to participate, that will permit to obtain reliable information as to the time during which specific publicity and/or broadcasted program is watched by TV watchers or heard by radio listeners, at home or in the car, whether drivers or passengers.
It is another object of this invention to obtain said information separately for specific broadcast channels.
It is a further object of the invention to obtain said information in real time.
It is a still further object of the invention to obtain said information by means of simple and inexpensive apparatus, which will not interfere with the normal operation of the TV converter or FM radio.
It is a still further object of the invention to provide a system and apparatus that will monitor all channels concurrently in real time, and not only a chosen one.
It is a still further purpose of the invention to provide a system and apparatus that will permit a very short timing of transmission and reception of signals relating to the desired information, and only by command.
It is a further object of this invention to provide such a system and apparatus that uses only licensed TV and radio channels dedicated and provided for such uses.
It is a still further object of the invention to provide such a system and apparatus that has no limits as to the detection zone or operation time and is not affected by parasitic leakage signals.
It is still further object of the invention to provide such a system not only for surveying TV and FM radio system but apply it to any other radio system installed in any kind of vehicles, cars, airplanes or boats, which might include receiver only like in TV converter or FM radio or transceiver for any kind of application, and can be AM, L-band, television sets, radar and so forth, either alone or in combination with the detection of FM stations. Moreover, the detected signal need not be LO signal generated by TV converter or FM radio only, but can be any signal generated in the car in relation the other radio system in use.
Other objects and advantages of the invention will appear as the description proceeds.